He responded with "how would it work"? I think he is referring to his feature request and is ignoring my payment renegotiation. He asked me to build this syste

He responded with "how would it work"? I think he is referring to his feature request and is ignoring my payment renegotiation. He asked me to build this system for him. He bought a web hosting account, and I deployed an instance of the system to his hosting. Show vendors can log into the public site. And he is the only one that can log into the admin area. How do I ask him how much value it provides him? Do I just point blank ask him how much he makes per year or per show?